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Bringing alien atmospheres into focus

Tau Bootis system

An artist’s impression of the Tau Boötis system. (Courtesy: ESO/L Calçada)

By Tushna Commissariat

It seems as if no sooner have I finished writing about exoplanets, then there is some more interesting news from the field and I am back at it.

Following last week’s story on the cosiest exoplanet system, today an international team of astronomers has used the European Southern Observatory’s Very Large Telescope (VLT) to carry out a detailed study of the atmosphere of a large “hot Jupiter” exoplanet. Specifically, it is a non-transiting exoplanet – one that does not pass across the face of its parent star.

Transiting is one of the methods researchers use to look for exoplanets – by searching for small dips in a star’s light-curve that occur when a planet crosses its face during a “transit”. But using this method means we can only find planets that transit their stars from the point of view of Earth. Another method, the radial-velocity method, looks for changes in the radial velocity of the star – tiny shifts that occur because of the gravitational pull of a planet orbiting it. But this method does not give us any information about the planet’s atmosphere, as no spectrum is seen. Hot Jupiters are a class of exoplanets with masses that are close to or more that the mass of Jupiter. They tend to orbit close to their parent stars and are easily detected.

Now, astronomers have managed to directly capture the faint glow from one of the first detected exoplanets, Tau Boötis b, and have both studied its atmosphere and measured its orbit and mass precisely for the first time – in the process solving a 15-year-old problem. Surprisingly, the team also finds that the planet’s atmosphere seems to be cooler higher up, the opposite of what was expected. Tau Boötis b is one of the closest known exoplanets and was previously only detected using radial-velocity measurements of the system, so the atmosphere was unknown.

The team used the CRIRES instrument on the VLT and high-resolution spectroscopy results, combined with specialized algorithms that ignore the host star’s much stronger signal, to tease out the weak signal of the planet.

The team also probed the planet’s atmosphere and measured the amount of carbon monoxide present, as well as the temperature at different altitudes by means of a comparison between the observations and theoretical models. Surprisingly, the researchers found that the planet has an atmosphere with a temperature that decreases higher up, contrary to other hot Jupiters, which show “temperature inversion” – an increase in temperature with height.

The results prove that high-resolution spectroscopy from ground-based telescopes can be very useful for the detailed analysis of the atmospheres of non-transiting exoplanets. In the future, the detection of different molecules will allow astronomers to learn more about the planet’s atmospheric conditions. By making measurements along the planet’s orbit, astronomers may even be able to track atmospheric changes between the planet’s morning and evening.

The paper on the new work will be published in Nature.

Graphene drumheads double as quantum dots

 

Physicists in the US have made quantum dots in graphene by simply introducing strain into the material. By creating tiny structures in which graphene is stretched like a drumhead, researchers say they are the first to show that charge carriers can be confined within the material by straining it. The results of this latest work could help in the development of graphene-based electronic devices such as transistors and optoelectronics components.

Graphene – a honeycombed lattice of carbon just one atom thick – is an excellent conductor of electricity thanks to the fact that electrons can whizz through the material at extremely high speeds with little resistance. This means that the material could one day be used to make transistors that are faster than any that exist today. However, graphene’s extreme conductivity is also a problem, because electronic devices made from the material cannot be effectively switched off. This not only wastes power, but also means that such devices cannot be packed onto computer chips in the same way that silicon components are today.

Lack of band gap

Although graphene is a type of semiconductor, it is unlike familiar materials such as silicon because it does not have an energy gap between its valence and conduction bands. Such a band gap allows a semiconductor to switch the flow of electrons on and off. Researchers have proposed various schemes to overcome this problem – for example cutting graphene into nanoscale ribbons or dots, or chemically modifying the material to create a band gap. While these schemes work in principle, altering graphene in these ways also damages the material so much that finished devices no longer have the desired high electron mobility.

Now, Joseph Stroscio of NIST in Gaithersburg, Maryland, and colleagues have modified the electrical properties in graphene simply by stretching the material. The researchers say that distorting graphene appears to have the same effect as applying a strong magnetic field and can produce quantum dots in the material. Quantum dots are tiny semiconducting structures in which electrons are confined in all three dimensions. It is this confinement that gives quantum dots unique electronic and optoelectronic characteristics, which can often be fine-tuned by adjusting the size of the structure. The ability to create semiconducting regions in graphene in this way might offer a way of making devices that offer both high electron mobility and a band gap.

Graphene “drumheads”

Stroscio’s team did its experiments on graphene “drumheads”. These were made by placing graphene flakes over a series of holes (each about 1 µm across) that was deeply etched in a silicon-dioxide wafer. The technique is rather like placing a sheet of plastic clingfilm over a tiny muffin tin. The silicon dioxide is an insulator and beneath it is a layer of conducting silicon, which acts as a gate electrode when a voltage is applied between it and the graphene.

The researchers then strained the graphene by pulling it up and away from the silicon dioxide with the attractive force from the tip of a scanning tunnelling microscope (STM). At the same time, the graphene was also pulled down using the electrostatic force from the silicon gate. Careful adjustment of the opposing forces allowed the team to have very precise control over the shape of the graphene drumheads, explains Stroscio.

Fictitious magnetic field

When the graphene is stretched or strained in this way, charge carriers (electrons and holes) in the material begin to move in circles rather than simply travelling in straight lines, as is usually the case. “Mathematically, the applied strain can be likened to a fictitious magnetic field,” says Stroscio, “and this field makes the charges travel in circles, just as they would in a real magnetic field.”

According to calculations performed by the researchers, the graphene drumhead is strained in the region around the STM probe tip, which produces a shape that looks like a circus tent as it pulls up the graphene sheet. The charge carriers are thus confined around the apex of the tent, in the same way as they would be confined in a quantum dot.

“Our experiments are the first to show that strained graphene confines charge carriers like in a quantum dot,” Stroscio told physicsworld.com. “Normally, you would have to cut out a nanosized piece of graphene to make a quantum dot out of the material, but our work shows that you can achieve the same thing with strain-induced pseudo-magnetic fields.”

The team, which includes scientists from the University of Maryland in the US and the Korea Research Institute of Standards and Science in Seoul, is now performing more comprehensive simulations to find out whether the size of the quantum dots in graphene can be tuned. “We are also busy looking at how intense the fictitious magnetic fields can become, and engineering different strain fields in graphene,” reveals Stroscio.

The research is reported in Science.

Hydrogel electronics makes its debut

A new type of hydrogel could make for high-performance energy-storage electrodes and biosensors. So say researchers at Stanford University in the US who have used the conducting polymer polyaniline (PAni) to develop a porous nanostructured material that they say has excellent electronic and electrochemical properties.

“Our material combines the advantages of hydrogels (which have a large surface area) and organic conductors, with their high electronic conductivity and good electrochemical properties,” team members Lijia Pan and Guihua Yu explain. “It could thus be used in high-performance electrochemical devices such as supercapacitors and ultrasensitive biosensors, like those used to detect glucose, for example.”

Hydrogels are 3D polymer networks that can hold a large amount of water and have a structure similar to that of biological tissue. Most hydrogels are based on non-conducting polymer matrices, however, which limits their applications in electronics. The researchers, led by Zhenan Bao and Yi Cui, have now used phytic acid, which is a good ionic conductor, to dope and crosslink the PAni in an effort to overcome this shortcoming.

Fast-forming gel

The team began by mixing two solutions. The first initiates the polymerization reaction while the second contains the monomer aniline and the doping phytic acid. A hydrogel forms in as little as three minutes, explains Yu, thanks to the fact that each phytic acid molecule contains six phosphorus groups that can interact with several polymer chains at once.

“We showed that we can synthesize the conductive polymer hydrogel in large quantities and also pattern it by inkjet printing and spray techniques,” says Pan. “This means that we might be able to fabricate electronic and electrochemical devices such as biosensor arrays and microsupercapacitors on a large scale fairly easily.”

The PAni hydrogel was found to have a high specific capacitance of around 480 F/g and a high rate capability (it charges and discharges energy very fast), which means that it might be ideal in applications such as electric vehicles and grid-scale energy storage. To compare, commercial carbon only has a specific capacitance of around 100 F/g.

Sensing glucose quickly

Spurred on by these results, the researchers decided to fabricate a glucose sensor by immobilizing the enzyme glucose oxidase (GOx) in the hydrogel. Glucose reacts with the GOx and its concentration in solution is monitored via electrochemical measurements using the GOx-PAni hydrogel electrode. “The electrode acts as an excellent interface between the biological (the enzyme GOx) and the synthetic (the electrode),” says Pan, “and the 3D conducting nanostructured framework allows the hydrogel to effectively collect electrons during the enzyme-catalysed glucose redox reactions.”

The hydrogel also reacts very quickly – in around just 0.3 s, compared with a response time of around 20 s for commercial glucose sensors, he adds.

The team says that it is now busy developing other novel hydrogels based on various conducting polymers. “We are also trying to push our new technology into areas such as high-performance lithium batteries, electro-chromic devices, neuronal electrodes and even electronic skin,” reveals Yu.

The research is reported in PNAS 10.1073/pnas.1202636109.

Putting a new twist on optical communications

If the lacklustre speed of your Internet connection is getting you down, help could soon arrive from the orbital angular momentum of light. That is because an international team of researchers has developed a prototype system that uses this previously unexploited property of electromagnetic radiation to boost the amount of information that can be transmitted using a given amount of bandwidth. Although the test transmission was done across just a few metres in a vacuum, the technology developed in this proof-of-principle application could find wider application in optical telecommunications.

The rate at which data can be transmitted using electromagnetic radiation is normally limited by how much of the electromagnetic frequency spectrum is used – a quantity referred to as the bandwidth of the system. However, electromagnetic radiation has other degrees of freedom in addition to frequency and researchers are keen to use these to develop multiplexing schemes that boost the amount of data that can be sent over a link. For example, photons have an intrinsic spin angular momentum that manifests itself in the polarization of light. This property has already been used to increase data transmission rates – one stream of data is transmitted using photons with vertical polarization, for example, and another stream using photons with horizontal polarization.

Orbital angular momentum

It turns out that light can also carry orbital angular momentum. This is a result of the phase fronts of the waves rotating relative to their direction of propagation to create a pattern resembling a corkscrew. Whereas spin angular momentum can take only two values, orbital angular momentum can, in principle, take an infinite number of values. This could, in theory, allow a large number of data channels to be created using a finite amount of bandwidth.

This orbital angular momentum was first considered as a possible means of quantum communication in 2001 by the Austrian quantum physicist Anton Zeilinger. The idea that classical information could also be encoded in the orbital-angular-momentum states of photons was then demonstrated in 2004 by Miles Padgett and colleagues at the University of Glasgow in the UK. However, while Padgett’s group proved that the principle could work, there was much to be done to produce a practical system.

The challenge has been taken up by Alan Willner and team at the University of Southern California, who, together with colleagues elsewhere in the US and in Israel, are the first to use orbital-angular-momentum states for multiplexing. Each data stream is encoded in the usual way using a series of on/off laser pulses. Then, separate streams of data are given a different orbital angular momentum before the beams are combined and transmitted. Finally, the different streams are separated in a process called “demultiplexing”.

No crosstalk

The different orbital-angular-momentum states are orthogonal, which means that there is no “crosstalk” between the beams. As a bonus, since quantum mechanics allows you to know both the orbital and the spin angular momentum of a photon at the same time, the researchers managed to perform both polarization multiplexing and orbital-angular-momentum multiplexing on their beams of light. This doubled the number of states available and allowed the transmission to reach terabit speeds.

“What impresses me most about the [research] is that it goes beyond a proof of principle to the point where the researchers’ results show meaningful amounts of speed,” comments Padgett. “It’s not just ‘let me prove the basic physics’ – they’re also putting in place lots of the supporting technology that would be needed in practice to build a runnable system.”

Atmospheric challenges

There is still much to be done, however. The test was conducted in a vacuum, with a transmission distance of only a few metres. Willner explains that the presence of an atmosphere can cause problems. “In the atmosphere there is turbulence,” he explains, “which tends to create crosstalk. As a result of clouds, wind or warm air, some of the energy from one twisted beam might appear on another twisted beam.” Absorption of the signal is another problem associated with transmitting through the atmosphere. Nevertheless, Willner remains optimistic. “We’re trying to increase the capacity and explore the limitations of propagation,” he says.

Using multiplexed transmission over an optical fibre is another possibility, according to Willner, who points out that researchers working at Boston University have already shown that orbital-angular-momentum modes can be transmitted over 1 km.

The research is published in Nature Photonics.

Frequency comb helps kill dangerous bacteria

Scientists in the US have used an optical-frequency comb – a laser that emits light at a range of equally spaced frequencies, like the teeth on a comb – to monitor how well a device designed to kill dangerous bacteria does its job. The comb was used to measure the concentrations of ozone, hydrogen peroxide and other reactive molecules in the stream of air and cold plasma produced by the decontamination device. The study reveals that decontamination is most efficient when both a plasma and hydrogen peroxide are present in the stream.

“Cold-air plasmas” – room-temperature gases of ionized air molecules – are widely used to kill dangerous bacteria, both in medical and food-processing environments. While the technique is good at dealing with antibiotic- and heat-resistant bacteria, the devices can be even more potent if the plasma is combined with an antibacterial chemical such as hydrogen peroxide. But understanding why this process occurs and how it could be improved is not easy because accurately measuring the relative abundances of different molecules in the stream – and how they interact – is tricky.

Sensitive teeth

Mark Golkowski and colleagues at the University of Colorado, along with Jun Ye and team at JILA in nearby Boulder, have shown that an optical-frequency comb – a device normally associated with atomic clocks and precision spectroscopy – can get round this problem to study molecules in the decontaminating stream. When light from the comb passes through the stream, the presence of a specific molecule or ion is signified by the absorption of a specific set of teeth. According to Golkowski, JILA’s frequency comb offers the “unique capability of an extremely sensitive measurement and one that also yields information about the interaction dynamics, since many molecules can be simultaneously observed on short timescales”.

As well as quantifying how much hydrogen peroxide is in the stream, the frequency comb also revealed that the addition of hydrogen peroxide did not affect the level of the toxic gas nitrogen dioxide in the stream. The team also found that the levels of ozone and nitrous oxide in the stream halved when hydrogen peroxide was introduced. According to the researchers it is difficult to predict the relative concentrations of these molecules using numerical modelling, and therefore the frequency comb has given them a unique insight into the chemistry of their stream.

The research also confirmed that a hydrogen-peroxide-rich stream can quickly kill bacteria up to 3 m from the source. The system proved very effective at disinfecting surfaces of potentially dangerous organisms including Staphylococcus aureus – a cause of pneumonia and other diseases – and Pseudomonas aeruginosa, which is often found on medical equipment.

The research will be published in IEEE Transactions on Plasma Science.

Planet-spotting

PW-2012-06-22-blogexoplanets-large.jpg

(Courtesy: Randall Munroe/Creative Commons)



By Tushna Commissariat

At first glance, the image above might remind you of a colour-perception test. But what one-time physicist and comic-designer Randall Munroe has done is to create a to-scale visualization of all the known 786 planets that we have discovered over the years – including the eight of our own system.

He has been particular enough to note that the size of some of these planets has been determined simply on the basis of their mass – meaning that they might, in actuality, be smaller and denser. Interestingly, this is not the first time that Munroe, who is behind the hugely popular xkcd.com webcomic, has had something to say about the billions and billions of exoplanets that we now know exist. In fact, in a previous comic, he talks about travelling in interstellar space, with one particular character agonizing about his partner’s apparent apathy over the wonder of all the worlds.

While Munroe’s newest comic is excellent, unfortunately, he is already out with the count. As of yesterday, the team behind NASA’s planet-finding Kepler telescope announced that it has found another two planets in its data. However, these two planets are caught in quite a clinch – they are closer to each other than any planetary system we’ve found to date.

The cosy system, mundanely called Kepler-36, contains two planets circling a subgiant Sun-like star that is several billion years older than the Sun. The inner world, Kepler-36b, is a rocky planet with a 14-day orbit. It is about 1.5 times the size of Earth and is 4.5 times as massive. The outer world, Kepler-36c, is a “hot Neptune” planet with a 16-day orbit that is 3.7 times the size of Earth and 8 times as massive.

The researchers point out that as the planets are so close to each other, from the surface of the smaller planet one would see the partner-planet as we see the Moon, only 4–5 times bigger, filling up its sky and presenting quite a spectacular view.

If Munroe’s first exoplanet comic does prove to be correct, I vote we point our spaceships towards this rather interesting system.

CERN calls press conference for 4 July…

By Hamish Johnston

We have heard from a reliable source that CERN will be holding a press conference on 4 July. This is the first day of the International Conference on High Energy Physics in Melbourne, Australia, where physicists working on the Large Hadron Collider (LHC) are expected to unveil the latest results in their search for the Higgs boson.

Earlier this week the Physics World editorial team played out a few scenarios regarding how CERN would deal with the possibly that data presented in Melbourne would tip 2011’s preliminary sighting of the Higgs to “discovery status”.

A big problem with an “official announcement” in Australia is that the country is a “non-member” of CERN – and therefore it seems very unlikely that the discovery would be unveiled in a country that hasn’t paid a significant chunk of the LHC’s price tag. Also, CERN’s PR guru James Gillies is on the record as saying that the Higgs announcement will be made in Geneva.

The only option, it seemed, was for CERN to organize a press conference in Geneva before or during the Melbourne conference to announce the discovery – and it looks like that’s what it has done.

But this introduces another problem. The press conference is scheduled for 09.00 Geneva time, presumably because this is 17.00 Melbourne time. However, this is 02.00 at Fermilab in Chicago – which is keen to emphasize the huge role that lab has played in the hunt for the Higgs. Oh, and 4 July is a national holiday in the US. Apparently, the Americans are not pleased!

Well, that’s enough speculation…I’ve got to get my ticket to Geneva booked!

Plasmons spotted in graphene

Two independent teams of physicists have been able to create and control “plasmons” – collective oscillations of conduction electrons – on the surface of graphene for the first time. Their experimental approach, dubbed “plasmon interferometry”, could be used to study a wide range of materials including superconductors and topological insulators. As the plasmons interact so strongly with light, graphene could be used to create new optical devices and even materials for invisibility cloaks.

Surface plasmons can interact with light at certain wavelengths to create surface plasma polaritons (SPPs), which are light-like excitations that propagate along the surface. SPPs often have shorter wavelengths than the associated light and so tend to confine the light to a smaller region than is allowed in free space. This concentrating effect is particularly useful for shrinking the size of optical circuits and can also be used to create “transformational optics” such as superlenses and invisibility cloaks. Structures that support SPPs have also been used as chemical sensors because they tend to enhance interactions between light and molecules.

Concentrating energy

Graphene – a honeycomb lattice of carbon just one atom thick – is expected to have plasmonic properties that are somewhat different to metals, where plasmons have been studied in detail. This is because the conduction electrons in graphene behave like “Dirac fermions”, which means that they travel through the material at near the speed of light. Graphene plasmons therefore concentrate electromagnetic energy into a much smaller region, which could be useful to researchers developing plasmon-based technologies. Because of these differences, however, conventional techniques for using infrared light to create and study plasmons do not work with graphene.

The two teams of physicists have used the sharp tip of an atomic force microscope (AFM) as a nanoantenna, which focuses a beam of infrared light into the graphene. One team includes Zhe Fei, Dmitri Basov and colleagues at the University of California, San Diego, along with collaborators in the US, Singapore and Germany. The other team is led by Frank Koppens of ICFO in Barcelona and includes scientists from CSIC in Madrid and the nanoGUNE research lab in San Sebastian.

Sharp tip

The AFM tip also interacts with plasmons that are already in the graphene and this affects how infrared light is reflected back from the tip to a detector. The teams can therefore detect plasmons in the material by scanning the tip across the surface of graphene and making measurements at a large number of locations. At each location, plasmons created at the tip radiate across the graphene like ripples on a pond until they are reflected at the edges. This creates an interference pattern of standing waves – an image of which is built up by scanning the AFM tip across the samples.

In both experiments the physicists found that the wavelengths of the plasmons are much shorter than those created by shining infrared light on metals – confirming the idea that graphene plasmons concentrate electromagnetic energy into a much smaller region than metal plasmons. The researchers were also able to tune the wavelength and amplitude of the graphene plasmons by changing an applied gate voltage, which could lead to the development of transistor-like devices in which light can be controlled electrically. While the properties of metal plasmons can be controlled by changing the size and shape of metallic nanostructures, such electrical tuning has not been demonstrated in metals.

“The gate voltage changes the density of mobile electrons in graphene,” explains Basov. “With more free electrons in the graphene, its electronic liquid becomes more ‘rigid’ and the wavelength of plasmonic oscillations is reduced, whereas their amplitude is enhanced.” One important consequence of this is that the gate voltage can be used to switch the plasmons on and off. As a result, Koppens believes that the research could lead to ultrafast optical switches. Other applications include better sensors and new quantum-information processing systems.

As for Basov, he is keen to develop plasmon interferometry as a new tool for studying a wide range of materials. “This new approach will be equally useful to probe the surface physics of many other exotic and interesting materials, among them topological insulators that conduct on the surface while remaining insulating in the bulk,” he says.

The research is described in two papers in Nature.

Should CERN scientists be encouraged to discuss ongoing LHC analyses with the outside world?

By James Dacey

With the International Conference on High Energy Physics (ICHEP in Melbourne just around the corner, the rumour mill has gone into overdrive over whether CERN scientists will be presenting findings that confirm last year’s initial sighting of the long-sought Higgs boson.

ICHEP will start on 4 July and will include presentations by scientists working on the two major experiments at CERN’s Large Hadron Collider (LHC) that are searching for the Higgs particle: CMS and ATLAS. It is presumed that these researchers will be discussing new data that either support or destroy the bumps that appeared in the datasets of both CMS and ATLAS last December, which both corresponded to a Higgs particle with an energy of roughly 125 GeV/c2.

Speculation about the state of play in the LHC analysis has been going on via the usual suspects in the blogosphere. This includes the mathematical physicist Peter Woit, based at Colombia University in the US, who writes in this post about how he has heard from both CMS and ATLAS that they are seeing data that strengthen the bump from last year. Meanwhile, the independent physicist Philip Gibbs, located in the UK, ponders the statistical significance of the new results. He concedes that he does not know how much new data have been analysed but speculates that if both experiments have reached the gold-standard “5-sigma significance” then they will not be able to resist combining their results for the Melbourne conference. If they do indeed do this, then by the standards of particle physics they will effectively be announcing the Higgs discovery in Australia.

Interestingly, there has been little on the blogs from the LHC researchers themselves over these latest developments in the Higgs hunt. CMS physicist Tommaso Dorigo, who is never usually one to shy away from informed speculation, prefers to discuss predictions for the existence of the Higgs made in 2010. Another CMS research and blogger, Seth Zenz, actively tries to ward off speculation. He is critical of the New York Times for running a recent article with the headline, “New data on elusive particle shrouded in secrecy”. Zenz says that there is nothing to hide and he asks politely if we can all wait patiently for another couple of weeks for the ICHEP conference.

The extent to which this silence is CERN-sanctioned is unclear, but it does appear that LHC scientists have a (possibly unspoken) agreement to keep quiet about their analyses with the outside world. You could argue of course that there are very good reasons for this, not least because this is an incredibly important and busy time in their scientific careers that requires complete focus.

From a scientific communication point of view, I reckon you could argue it both ways. On the one hand it will be a lot “neater” to wait until the finding is beyond any doubt before announcing the discovery to great fanfare, embarking on the Higgs boson grand tour, scripting the Hollwood film, etc. But on the other hand, by depriving the general public of your thoughts (and by this I mean depriving anyone who is not involved with the LHC), you are depriving them of a fantastic insight into how science really works. As any researcher knows, the scientific process is messy. It’s about carefully tweaking experiments and rigorously testing statistical data. So, for CERN to remain quiet while it carefully choreographs a public discovery announcement could create a false impression of science as a series of “Eureka moments” occurring among a secret society of knowledgeable folk.

Let us know what you think in this week’s Facebook poll.

Should CERN scientists be encouraged to discuss ongoing LHC analyses with the outside world?

Yes, they should discuss the scientific process in the open
No, they should wait until conclusions are firmly established

Let us know by visiting our Facebook page. As always, please feel free to explain your choice by posting a comment on the poll.

hands smll.jpg

In last week’s poll we asked you to place yourself in a scenario that could soon become a reality for a few certain people if the Higgs boson is confirmed. We asked you tell us what you think would be the best thing about winning a Nobel prize, by selecting one from a list of options. People responded as follows:

The recognition that my field would receive (43%)
Freedom to do the science that I want to do (30%)
Securing a place in the history of science (17%)
I wouldn’t want to win (6%)
The fame and all that comes with it (3%)

The poll also attracted some interesting comments, including some alternative benefits that could come from winning the prize. Alan Saeed wrote: “I think the most rewarding part of a Nobel prize is the inspiration that it will infuse in the young minds of the country from where the recipients came”. Robert Ley, in the UK, made the good point that: “It would be interesting to see if this poll returns the same result if the votes were made anonymously!” One commenter, who probably wouldn’t be altered by anonymity, is Alan Timme who wrote (possibly with his tongue in cheek) that the best thing about a Nobel prize would be: “Rubbing it in the face of my doubters!”.

Thank you for all your comments and we look forward to hearing from you in this week’s poll.

Introducing Agent Higgs

By Tushna Commissariat

“Dodging the physicists of the world is no easy task! You need all your wits about you, and the steady hand of a secret agent to stay out of sight.”

Agent Higgs

Agent Higgs

If that sentence has left you wondering who or what is hiding from physicists, apart from the so-called elusive Higgs boson, you have hit the particle on the head! In a bid to keep the Higgs even further from physicists’ clutches, physics educator turned science-related games designer Andy Hall has developed a game for iOS devices known as “Agent Higgs”.

“The whole world is after the elusive Higgs particle. Accelerators the size of cities are being used to create truly awesome concentrations of energy in a vast number of collisions. We’ve detected all the other particles of the Standard Model. Muons, quarks, neutrinos, the whole gambit. But not the Higgs. How is it avoiding detection?” asks the tantalizing game description. Well, apparently it’s thanks to the help of gamers the world over.

In the game, you are encouraged to help the Higgs hide from nosy particle detectors, by hiding “him” behind a slew of the other known subatomic particles such as electrons, neutrinos and muons. Hall, who set up TestTubeGames in 2011 in an attempt to make complex scientific topics fun and interesting, is hoping that Agent Higgs will introduce people to particle physics in a fun way.

According to Hall, “The rules of the game are based on the fundamental forces. Use the weak force to get particles moving, or to make them decay. Use the electromagnetic force to make particles attract or repel. The physics introduced in this game even extends to matter–antimatter annihilation and neutrino oscillation.”

The game has more than 100 levels that slowly and steadily introduce particle-physics laws that gamers can use to block the Higgs from the detector’s view. Hall says that he designed the game to be challenging yet engaging.

The game has been released worldwide through the iTunes Store and is priced at $0.99 in the US. You can download the game from the iTunes Store here.

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